In general, home appliances such as home network systems and the like include various sensors.
For example, a conventional pyroelectric infrared ray sensor to mainly sense the presence/absence of a person detects the temperature difference between heat radiated from a moving human body and a background space, so that the absence or the presence of the user can be detected.
However, the pyroelectric infrared ray sensor does not detect the presence state of the person when the person moves at a low speed or stops. In addition the pyroelectric infrared ray sensor may erroneously operate due to the interference resulting from the temperature variation caused by heating/cooling devices such as an indoor air conditioner or a heater.
In addition, the pyroelectric infrared ray sensor cannot sense an optic angle when the optic angle exceeds a predetermined range within the line of sight even if a sensing angle of the pyroelectric infrared ray sensor is increased by using a Fresnel optical lens.